I have previously invented a contour shear rest for use in a plane shearing machine to simulate, in a three dimensional deep-pile fabric the effect obtained by sewing together small animal pelts, such as mink. The shear rest there provided has a contour surface made up of elements forming a mirror image of the desired contour. The contour surface is formed so that the length of the travel path of the fabric drawn across its face is uniform. See my co-pending U.S. application Ser. No. 719,017 which has now been assigned U.S. Pat. No. 4,102,023.
In endeavouring to utilize the contour shear rest of such invention for the commercial production of contour sheared deep pile fabrics, it was discovered that for purposes of continuously maintaining a precise interrelationship between a patterned web of high pile fabric and a contour shear device incorporating such contour shear bar, it was desirable to continuously make adjustments in the transverse alignment of the web relative to the contour shear work station. It was also desirable, during operation, to maintain a continuously variable but optimized longitudinal tension upon the web because thereby the transverse width of the patterned web could be influenced and hence bring and maintain the web into a desired exact transverse registration with the contours of the contour shear device. Inherent structural variations seemingly tend to occur in a continuous web of pile fabric so that it does not appear to be feasible to merely initially at a start up adjust the transverse alignment and longitudinal tension of a continuous web of pile fabric relative to a transversely extending work station since variations can develop during machine operation after the web has advanced even relatively short distances. Consequently, for purposes of plant operation, particularly an automated plant operation, it is desirable to have a control system for transversely aligning and continuously, variably longitudinally tensioning a continuous web relative to a transversely extending work station. So far as I am aware, this type of control problem has never previously been met or solved through the provision of an appropriate control system.
In addition, it has also been determined that when employing a contour shear device of the character above described, it is desirable to employ a contour electrifier for subsequent polishing operations. As those skilled in the art appreciate, a machine known as an electrifier is used in the processing of pile fabrics, fur, and similar yardage to place the fur or pile in a desired or proper finished condition. Generally speaking, the function of an electrifier is to brush, comb, beat, polish, and/or iron which is accomplished by the application to the pile or fur of a rapidly rotating heated roll which has a grooved surface. Work pieces are fed continuously to the roll with the pile or fur faced toward the roll and an apron of canvas or other suitable web support means which will insure the desired exposure of the pile to the electrifier cylinder is so mounted with respect to the roll that the fabric is fed between the apron or support means and the roll. Typically, the temperature of the surface of an electrifier roll is critically controlled.
In processing by an electrifier, a fabric which has been contour sheared by a contour shear device such as described in my above referenced invention, it has been found that undesirable variations in the product pile finished characteristics can be obtained owing to the inability of prior art electrifiers to conform in their surface application characteristics to pile contours. So far as I am aware, no one has heretofore succeeded in providing electrifiers whose working surfaces are adapted to conform to contours previously formed in a pile or fur work piece.
Further, it has now been determined that, in the processing of, for example, contour sheared high pile sliver knit fabrics, it would be desirable to use a train of contour processing units in some desired processing sequence with the individual processing units being either a contour shear device or a contoured electrifier device. Since problems of alignment, tensioning, and registration of web relative to contour processing unit can arise at each unit in such a train, it is desirable to have a system for controlling a continuously moving web being processed by a train of such contour processing units which permits the web to be aligned for all units with a minimum of control hardware. If, for example, a single separate control unit of the type necessary for achieving alignment, registration and tensioning, as desired, were necessary at each individual contour processing unit, manufacturing costs would apparently be substantially and undesirably increased. Hence, there is a need for using a single control system to simultaneously and effectively control a web during its passage past a plurality of contour processing units.